1-Imidazolidinecarboxylic acid, 2,5-dioxo-4,4-diphenyl-, ethyl ester → HCID 20329017, compound

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Reaction Steps

Under an argon atmosphere, 4.32 g (0.09 mol) of sodium hydride (50% dispersion in mineral oil) was placed in a dry, 1 liter, 3-necked round bottom flask equipped with a mechanical stirrer and thermometer. The sodium hydride was rinsed with 250 ml of dry hexane. To the washed material was added 29 g (0.09 mol) of 3-carbethoxy-5,5-diphenylhydantoin (1) [L. Call, Monat. Chem. 101:228(1970)] dissolved in 250 ml of dry dimethylformamide (DMF). After stirring for one hour, hydrogen gas evolution ceased. Then 20.9 g (0.1 mol) of ethyl-5-bromovalerate was added and the reaction stirred overnight at room temperature. The DMF was removed under high vacuum and the residue partitioned between 500 ml of ether and 300 ml of water (H2O). The ether phase was separated, washed with saturated sodium chloride solution, dried over anhydrous magnesium sulfate, filtered, and evaporated to give an oil. This oil was stirred at 5° C. for 3 hours in 500 ml of 2 N sodium hydroxide. Acidification with dilute hydrochloric acid precipitated an oil that was crystallized from ether and recrystallized from aqueous methanol to give 5 g of 1-(4-carboxybutyl)-5,5-diphenylhydantoin (4) as white crystals, mp 207° C.

Provenance & Evidence